The heat flux from the human skin to the environment was measured with heat flux transducers placed all over the skin surface of a male subject .The total heat flux from the unclothed subject was 113 W at the room temperature of 20 C, and 84.9 W from the subject clothed in a loosely fitting training shirt. The heat flux distribution was found to be approximately symmetrical in terms of the centerline of a trunk without clothes. Its correspondence with the skin surface temperature was obtained, approximately. A constant temperature bath made of a stainless steel cylinder was constructed in the shape of a human body. The total heat flux measured by the previous transducers agreed fairly well with the total electric energy supplied to a constant temperature bath of this model.